wedge wire screen specification

Wedge wire screens (also known as profile wire screens) are precision-engineered filtration/separation devices widely used in water treatment, mining, food processing, and oil & gas industries. Their specifications are critical to ensuring optimal performance, durability, and compatibility with specific applications. Below is a detailed breakdown of key technical parameters:

1. Material Specifications

The choice of material directly impacts corrosion resistance, temperature tolerance, and service life. Common materials include:

Stainless Steel Alloys (Most Popular):

304/304L: Cost-effective, suitable for non-corrosive/lightly corrosive environments (e.g., municipal water treatment, food processing). Resists oxidation up to 870°C (1600°F).

316/316L: Enhanced corrosion resistance (contains molybdenum) for harsh conditions (e.g., seawater, acidic/alkaline solutions, chemical processing). 316L offers lower carbon content to prevent sensitization.

317L: Superior to 316L in resisting pitting and crevice corrosion; ideal for high-salinity or high-temperature applications (e.g., offshore oil drilling).

Specialty Alloys:

Hastelloy C-276: For extreme corrosive environments (e.g., concentrated acids, chemical reactors) with temperature resistance up to 1093°C (2000°F).

Duplex Stainless Steel (2205): High strength + corrosion resistance; used in high-pressure applications (e.g., oil well screens, mining slurry separation).

Carbon Steel: Low-cost option for non-corrosive, low-pressure applications (e.g., industrial waste screening with neutral pH).

2. Structural & Dimensional Specifications

2.1 Core Structural Components

Wedge wire screens consist of two key parts:

Wedge Wire (Profile Wire): The filtering medium, with a triangular / (trapezoidal) cross-section. Key parameters:

Wire Height (H): 1.5 mm – 12 mm (varies by application pressure; higher height = better flow capacity).

Wire Thickness (T): 0.8 mm – 5 mm (thicker wires = higher mechanical strength; used for heavy-duty screening like mining).

Tooth/Edge Design: Sharp edges (for fine particle separation, e.g., food processing) or rounded edges (for abrasive materials, e.g., sand screening) to prevent wire wear.

Support Rods (Backbone): Reinforce the screen structure; typically round or rectangular in shape.

Diameter/Size: 3 mm – 15 mm (larger rods = higher load-bearing capacity).

Spacing: 20 mm – 200 mm (adjusted based on screen size and application pressure; closer spacing = more stability).

2.2 Screen Opening (Slot Size)

The opening size determines the particle retention capability and is the most critical parameter for filtration. Specifications include:

Range: 0.02 mm (micro-filtration, e.g., pharmaceutical processing) – 50 mm (coarse screening, e.g., gravel separation).

Tolerance: ±0.01 mm (for fine openings) to ±0.5 mm (for coarse openings) to ensure consistent filtration.

Opening Pattern: Linear (most common, for uniform flow) or staggered (higher opening area, used for high-flow applications like water intake).

2.3 Overall Dimensions

Customizable to fit equipment (e.g., filter housings, centrifuges, vibrating screens). Standard ranges:

Flat Screens: Length 300 mm – 6000 mm; Width 100 mm – 2000 mm.

Cylindrical Screens (Tubes): Diameter 50 mm – 1000 mm; Length 500 mm – 8000 mm.

Conical Screens: Taper angle 5° – 30°; Top diameter 100 mm – 800 mm; Height 300 mm – 3000 mm.

3. Performance Specifications

3.1 Flow Rate

Measures the volume of fluid the screen can process per unit time, influenced by opening area, slot size, and screen size.

Unit: m³/h (cubic meters per hour) or GPM (gallons per minute).

Typical Range: 5 m³/h (small cylindrical screens) – 500 m³/h (large flat screens for water treatment plants).

3.2 Pressure Rating

Maximum pressure the screen can withstand without deformation or damage.

Vacuum to Positive Pressure: -0.09 MPa (vacuum applications, e.g., suction filters) to 10 MPa (high-pressure applications, e.g., oil well completion).

Burst Pressure: 1.5 – 2x the maximum working pressure (safety margin).

3.3 Temperature Resistance

Depends on material (see Section 1):

Stainless Steel (304/316): -270°C to 870°C (suitable for cryogenic to high-temperature fluid processing).

Specialty Alloys (Hastelloy): Up to 1093°C (for extreme heat applications like incinerator flue gas treatment).

3.4 Corrosion Resistance

Evaluated via industry standards:

Salt Spray Test (ASTM B117): 316L stainless steel typically passes 1000+ hours without red rust.

Acid Immersion Test: Hastelloy C-276 resists 5% H₂SO₄ (sulfuric acid) at 60°C for 1000+ hours.

4. Manufacturing & Quality Specifications

4.1 Production Standards

Welding: TIG (Tungsten Inert Gas) welding for wedge wire and support rods (ensures strong, corrosion-resistant joints).

Surface Finish:

Electropolishing: Reduces surface roughness (Ra < 0.8 μm) for food/pharmaceutical applications (prevents particle buildup).

Passivation: Enhances stainless steel corrosion resistance (forms a protective oxide layer).

Sandblasting: For industrial applications (improves adhesion of coatings, if needed).

4.2 Quality Certifications

ISO 9001: Quality management system compliance.

ASME BPE: For pharmaceutical/food-grade screens (ensures hygienic design).

API 13C: For oil well screens (meets oil & gas industry standards).

5. Application-Specific Specifications